Automatic tool changing system



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United States Patent Office 3,412,459 AUTOMATIC TOOL CHANGING SYSTEM John C. Hollis, Cincinnati, Ohio, assignor to Giddings & Lewis Inc., a corporation of Wisconsin Continuation of application Ser. No. 784,550, Jan. 2, 1959. This application Sept. 5, 1967, Ser. No. 666,237 38 Claims. (Cl. 29568) ABSTRACT OF THE DISCLOSURE A tool changer for a horizontal spindle machine tool, with a tool storage matrix, and a tool carrier for transferring tools over successive longitudinal and lateral paths between the spindle and the matrix, the tool carrier being horizontally movable along a track to move a tool between the matrix and an intermediate, tool exchange station laterally adjacent the spindle, and laterally therefrom into alignment with the spindle.

This is a continuation of my application, Ser. No. 784,- 550, filed Jan. 2, 1959 and now abandoned.

Description of the invention This invention relates to a machine tool and more particularly to an automatic tool changing system and apparatus for machine tools.

In general, it is an object of this invention to fully automate the supply of tool elements employed in a machine tool for performing machining operations on a workpiece. More specifically, it is an object to provide an apparatus for use in conjunction with a machine tool which provides storage space for an assortment of tool elements, such as drills, taps, or milling cutters, and wherein a particular tool element is automatically selected and transferred from the place of storage and in serted in the machine tool spindle for power operation.

"More specifically, it is an object to provide an automatic tool changing system and apparatus for machine tools such as boring, drilling, milling and tapping machines, by means of which system and apparatus a plurality of tool elements adapted to be mounted in the machine to carry out different machining operations or steps are stored in a matrix associated with the machine, and under record control, a particular tool element is hunted, selected from the matrix and transferred to the machine where it is mounted for operation on the work, and eventually returned to the matrix upon completion of the machining step carried out with the tool element.

Another object is to provide an automatic tool changing system in which the tool elements are stored in a random arrangement in the matrix, and in which the tool element is selected directly rather than by the place where it is stored.

A related object is to reduce the complexity of the storage apparatus, the transfer apparatus, and the control apparatus by providing random access tool changing wherein the tool elements are stored at random in a storage matrix and selected in response to identification carried directly by the tool elements.

Heretofore, it has been known to provide a storage arrangement for a plurality of tool elements, in which the individual tool elements are identified by their place in the storage apparatus, and it has been possible to con trol certain functions of the machine tool by the movement or extraction of the tool element from the storage apparatus. To identify the tool element in such systems requires actuating means in each storage place and a control system responsive to the actuating means for indicating the control function. It has been observed that in such systems the means required to identify the tool ele- 3,412,459 Patented Nov. 26, 1968 ments becomes exceedingly elaborate and complicated. It is now proposed to provide a means of identifying the tool elements which is in a more concise form, by tagging each tool element of a set with means of identification to uniquely distinguish it from others of the set, and utilizing control means which is responsive to the identification means on each tool element, for operating the apparatus to transfer the selected tool elements between the storage matrix and the machine tool.

A further object is to provide a random access system wherein operations of the apparatus for hunting and tool changing, are carried out in a rapid manner during dead periods in the operation of the machine tool. It is, therefore, an object to provide a system and apparatus which makes it possible to use a natural tool changing cycle in conjunction with the controlled operation of the machine tool for machining a workpiece.

Another object is to provide a system which is capable of storing a large number of tools and which includes apparatus relatively massive and of substantial weight to provide the storage space, yet so arranged and operated in association and conjunction with the machine tool that the weight does not impair the alinement of the elements of the machine tool.

A further related object is to maintain machining accuracies obtainable with the machine tool by having the tool changing apparatus as simple and light weight as possible, including that part of the apparatus which transfers the tool elements between the storage matrix and the machine tool spindle.

Another object is to provide a drive for the tool changing apparatus which derives its power from the machine tool transmission, thereby reducing complexity and cost.

Another objectis to provide a system allowing machine tools which are now record controlled for part of their operation, for example, as to speeds and feeds, to be fully automated by including a system for automatic tool changing.

, Another object is to provide an automatic tool changing system which is adapted for use in association with standard types of machine tools, and which requires a minimum amount of modification to adapt standard machine tools to receive the system.

Further objects will appear from the following description taken in connection with the accompanying drawings, wherein:

FIGURE 1 is a perspective view of a boring, drilling, milling, and tapping machine embodying an automatic tool changing system constructed in keeping with this invention;

FIG. 2 is a fragmentary sectional view taken in the plane of lines 2-2 of FIGURE 1, through the machine tool head;

FIG. 3 is a schematic view illustrating the means for supplying power to operate the tool carrier;

FIG. 3a is a detail view of one of the drive gears;

FIG. 4 is a view illustrating the drive means for operating the drawbolts in the matrix sockets;

FIG. 5 is a view illustrating an adapter for a tool element bearing coded information in the form of a systematic arrangement of marks on the shank;

FIG. 6 is an enlarged fragmentary detail view of the identification marks in the shank of the adaptor;

PG. 7 is a front view of the adaptor shown in FIG. 5;

FIG. 8 is a fragmentary sectional view taken through the matrix;

FIG. 9 is a view in elevation showing the reading device in association with a tool element containing sleeve of the matrix;

FIG. 10 is a schematic illustration of a control circuit including the electrical components of the reading head;

FIG. ll is a chart illustrating a code system for identifying a set of tool elements;

FIG. 12 is an enlarged fragmentary view in front elevation of the tool carrier apparatus, taken from the left in FIG. 3;

FIG. 12a is a sectional view taken in the plane of lines 12a--12a of FIG. 12;

FIG. 13 is an enlarged sectional view taken substantially in the offset planes of lines 13-13 of FIG. 14;

FIG. 13a is a sectional view taken in the plane of lines 13a13a of FIG. 13;

FIG. 14 is a fragmentary view of the gear drive included in the tool carrier head;

FIGS. 15 and 16 are stop motion views illustrating an alternative form of holding means embodying an arrangement to orient a tool element adaptor; and

FIG. 16a is a sectional view taken in the plane of lines 1611-1611 of FIG. 16.

While the invention is susceptible of various modifications and alternative constructions, a, preferred embodiment hereof has been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific form disclosed, but, on the contrary, the intention is to cover all modifications, alternative constructions and equivalents falling within the spirit and scope of the invention as expressed in the appended claims.

General machine organization Turning now to the drawings, the invention has been shown in association with a machine tool (FIGURE 1) such as a horizontal boring, drilling and milling machine, including a bed providing way surfaces 10' to support a saddle for movement lengthwise of the bed, the saddle carrying a table 11 which is traversable on way surfaces 10" provided by the saddle. The bed also carries an upright column 12 fashioned with vertical way surfaces for slidably receiving a vertically adjustable head 13. A horizontal power driven spindle 14 is included in the head 13 for operating a tool element T to perform machining operations on a workpiece carried by the table 11. This invention has particular but by no means exclusive utility in connection with a machine tool of the type shown, and therefore the showing of the machine tool has been made virtually schematic to simplify the description. However, it will be understood that it is preferred in connection with such a machine tool that the position of the spindle 14 may be adjusted vertically by means of adjusting screws 15 cooperating with the head, and that drives and power feeds are provided for the operation of the table and the head. The power driven head 13 is shown in FIG. 2 to include a drive transmission 16 and it is preferred that an electric drive motor 17 be mounted for operation of the machine tool spindle via the drive transmission 16.

Tool changing apparatus In addition to these standard elements of a machine tool, as shown in FIG. 1, according to the present invention the exemplary machine tool also includes a matrix 20 for storage of a set of tool elements 21 each of which may be mounted in the machine tool spindle. The matrix 20 is defined by an annular drum revolvable about an axis parallel to the axis of the machine tool spindle. The drum is supported on the vertically adjustable head 13 adjacent the rear end of the latter, by means of a pair of idler wheels 23 mounted for carrying the drum in offset relation to the column 12. A bracket 24 fixed to the head 13 is utilized to support the idler wheels. To revolve the drum 3 power driven sprocket 25 (FIG. 2) connects the drum to a gear transmission 26 which, in turn, is coupled to and operated by the drive transmission 16 for the spindle 14.

For the purpose of providing means for transferring a tool element between the matrix 20 to the spindle 14,

in keeping with the invention, the head includes mounted above the spindle 14 a tool carrier 27 having dual means which may be operated to extract a tool element 21 from the matrix 20 for transfer to the machine tool spindle 14 at the same time the tool element T mounted in the spindle is extracted and returned to the matrix. In order to perform these functions the tool carrier 27 (FIGS. 1 and 12) includes a pair of heads 30, 31 slidably mounted for independent longitudinal movement on an H track 33 which extends between the storage rack or matrix 20 and the machine tool spindle 14. Each head has an arm 35, 36 which extends radially and is adjustable in length, and supports means adapted to hold a tool element 21. In the operation of the system, to hunt a desired tool element the drum is revolved to position the tool element at a station adjacent the right end of the track 33. This position may, for convenience, be called the receiving or loading station for the tool carrier, and in the present case is located in vertical alinement with the track 33 of the tool carrier assembly. With the drum stationary, means included in the head 31 on the upper edge of the track is caused to operate the holding means to extract the selected tool element from the matrix for transfer to the spindle. This head 31 on the upper edge of the track is moved to the forward end of the track, which, as will be evident in FIG. 1, is a separate indexable section. By indexing the forward track section 180 the head carrying the tool element 21 is swung to a position below the track adjacent the spindle, and the holding means may be operated to insert the tool element in the spindle.

The annular drum 20 defines a matrix for storage in association with the machine tool spindle 14 of a set of tool elements 21 each of which is adapted to be mounted in the machine tool spindle for carrying out a machining operation. In the exemplary form of the invention illustrated, the annular drum is constructed of a pair of spaced annular plates 38, 39 connected together by a plurality of sleeves 41 equally spaced around the drum. For drive purposes the teeth of the sprocket 25 are fashioned as to mesh with the spaced sleeves 41, so that the sprocket turns the drum about its axis. As shown in FIG. 2, the sprocket 25 is in face to face engagement with the inner surface of one of the annular plates 38 forming the drum, and is held against the latter by means of a bearing disc 43 and spacer 44. The idler bearings 23 are constructed in a similar fashion, each consisting of a pair of plates 45, 46 separated by a spacer 47.

In order to receive a tool element 21 each sleeve 41 is formed as shown in FIG. 4, to provide a socket 51 for receiving the tapered shank 52 of a standard type adaptor 53 (FIGS. 5 and 7) for holding the tool element, the socket 51 being formed by a bore 'Within the sleeve which is tapered to fit the shank of the adaptor. The adaptor 53 will be seen to have a polygonal, essentially square collar or flange formed with axial slots 61 at each corner (FIG. 7), which give flange the appearance of a cross in elevation, as will be seen from FIG. 7. The standard keys 63 (FIG. 2) fastened on the nose of the machine tool spindle 14 fit tightly in diagonally opposite axial slots 61 when the adaptor is seated in the socket 65 of the machine tool spindle. It will also be noted that the flange 60 on the adaptor 53 has grooves 67 along the opposite parallel side edges. With this latter provision the adaptor can be securely held during the transfer operation in a manner which will be described more fully hereinafter.

A power operated drawbar or drawbolt mechanism 70 may be provided as shown in FIG. 2, in the machine tool spindle 14 for locking the tapered shank of the adaptor 53 tight in the socket of the spindle as a final power operated and automatically controlled step in the transfer of a tool element from the matrix to the spindle. The drawbolt mechanism, by reverse operation, may also be used to provide a means for positively ejecting the tool element from the spindle socket after a machining operation has been completed with -a particular tool element, and as part of the automatic operation to exchange that for a diiferent tool element. This drawbolt mechanism includes a drawbolt shaft 71 mounted for rotation in the hollow center of the spindle and extending into the socket of the spindle. The threaded end of the drawbolt in the socket is adapted to be received in a threaded opening 72 provided in the end of each tool element adaptor 53. The drawbolt shaft 71 is driven by the planet carrier 73 of a speed reduction unit 73' operated by the spindle motor 17.

A drawbolt mechanism may also be provided in association with each socket 51 defined in each sleeve 41 in the matrix to provide a power operated clamp to secure a tool in the socket. As shown in FIG. 4, each such drawbolt mechanism comprises a rotatable drawbolt 75 mounted by means of a bearing 76 in the sleeve 41 and having a threaded end 79 adapted to be received within the threaded recess 72' in each of the adaptors 53. Means are provided for connecting the machine tool transmission to the drawbolt 75 of the sleeve 41 containing a selected tool element when the sleeve is positioned at the receiving station for the tool carrier. To achieve this result a shaft 80 is mounted on the machine tool head 13 by means of a bracket 81, which shaft 80 is connected by a belt drive to a pulley 83 driven from the machine tool spindle drive. The shaft 80 is positioned so that when the drum defining the matrix is stopped in position to transfer a selected tool element to the spindle, the sleeve 41 in the matrix which contains the selected tool element is alined with the shaft 80 for operating the drawbolt contained therein. To drive the drawbolt 75, an electric clutch 84 is energized so .as to draw the armature 84' mounted on the end of the drawbolt 75 in the drum, into frictional engagement with friction surfaces 84" on the face of the clutch 84.

Tool carrier The tool carrier 27 provides for transferring a selected tool element 21 between the storage matrix and the spindle 14 while simultaneously returning a second tool element extracted from the spindle, to the matrix. To carry out these functions, the dual heads 30, 31 of the tool carrier support holding means independently operable to grip a tool element during transfer of the latter by the heads between the sockets of the matrix and spindle. In order to facilitate their being held securely, the tool elements are gripped by means of a grooved collar or flange 60 on the adaptor 53, which collar is accessible, as Will appear from FIGURE 1, when the tool elements are mounted in the sockets of either the spindle 1-4 or the matrix 20. Referring to FIGURES l and 3 for the details of the tool carrier, it will be seen that the pair of independently movable heads 30, 31 of the tool carrier are bodily slid-able along opposite sides of the H track 33 which is supported above the machine tool spindle 14. The track 33 includes a fixed section 33' which is mounted on a bracket 90 and extends to a point adjacent the drum 20, and an indexable section 33" which extends forwardly of the machine tool head 13 to a point adjacent the machine tool spindle 14. The indexable section 33" of the track is rotated by an indexing gear 34 shown in FIG. 3 meshing 'with a drive gear 34' fast on a shaft extending rearwardly from the indexable section 33" of the track toward the matrix. The indexing gear 34 is driven by the transmission for the spindle. Included in the drive for the indexing gear 34 is a reversing clutch A on the same shaft as drive gear 34". The drive gear 34" carries a block 34 shown in FIG. 3a to be engageable with a fixed stop on the frame of the machine. With this arrangement, by selecting the proper gear ratio, the shaft 91 connected to the indexable section 33 of the track is indexed 180 by turning the drive gear 34" through the angle to swing the heads 30, 31 between opposite positions above and below the track. In FIGURE 1 the track section is shown in the process of moving the heads. As shown in FIG. 3, for example, the head member 31 is on the under edge of the indexable section of the track so as to be positioned adjacent the spindle 14. In the present case the radial distance between the track 33 and a sleeve 41 of the storage drum when positioned so as to transfer a tool element is about the same as the distance between the track and the spindle 14. It is contemplated, moveover, that other storage arrangements may be used in which this relation may vary. A transfer of a tool element from the drum to the machine tool spindle, or vice versa, therefore, requires little, if any, movement of the tool element radially, except if it is desired to draw the tool element to a position adjacent the track during transfer. With the arrangement shown, enough space is providedin a passage 92 through the head 13 so as not to ordinarily require a tool element to be moved radially, in order to transfer the latter between the matrix and spindle. To carry the tool elements longitudinally of the spindle, and in the present instance through the passage 92 in head 13 of the machine tool, the tool carrier provides arms 35, 36. The arms 35, 36 are made adjustable so that they may be drawn inwardly to a position adjacent the track for storage purposes, and if desired, to move a tool element radially. Since the arms 35, 36 are of the same construction, the following description which for convenience is directed to the arm 35, may be considered to apply to either arm.

Supported by the tool carrier head 30, therefore, the arm 35 is extensible in length and includes a rod 95 slidably mounted in the head 31. The rod '95 is joined by a crossbar 96 to a plate which provides a holding means which may be operated to grip the tool element adaptor. For moving the rod 95 and thereby adjusting the length of the arm 35, a rack and pinion drive 101 (FIG. 14) is provided, with the teeth 102 for the rack fomed in the rod 95 and cooperating with the pinion 106 rotatably mounted in the head 30. As shown in FIG. 3, which is a schematic illustration of the drive and thus is not intended to depict the exact physical relationship of the elements of the drive, to rotate the pinion 106, power is supplied alternately by a power driven screw 107 mounted in the machine tool head adjacent the spindle, used when the head 30 is located at that end of the track 33, or a power driven screw 110 mounted on the machine tool head adjacent the end of the track 33 located near the drum, and used when the head is located for operation at the drum. Both screws 107, 110 are coupled to and operated by the spindle drive. To drive the pinion 106 from one or the other of the power screws 107, 110, the rotation of the screws is translated to longitudinal movement by a hollow shaft 111 or a nut 112 threadably receiving the respective screw. The hollow shaft 111 is connectable by a lug 111 to the drive mechanism within the head 31. In a similar way, the screw 110 is connected to the drive mechanism within the head by a nut 112 and lug 112'. Referring to FIG. 14, it will be seen that the lugs 111 and 112' are connected to a longitudinally movable shaft defining a rack 113 which drives the pinion 106 through a gear train.

Movement of the drive mechanism for the holding means associated with each head 30, 31, due to the weight of a tool element carried thereby, is precluded by a bidirectional coupling device 93 drivingly interposed between elements in the drive train connecting the pinion 106 and pinion 114. The device, shown in FIGS. 13 and 13a, is operative to transmit motion and power from the pinion 114 to the pinion 106, but couples the drive to a stationary part preventing back spinning of the pinion 114 when the latter is not afiirmatively moved. Reference is made to my copending application Ser. No. 473,527, now U.S. Patent No. 2,838,055 entitled Machine Tool Turret for a complete description of the coupling, however for present purposes the following brief description is provided.

The bidirectional coupling is mounted in a cylindrical recess 93' within the head and includes a driver element 94 consisting of three equidistantly spaced prongs 94 having facing straight sides, the driver element being splined on the shaft 114' so that it turns with the shaft as the latter is driven by the gear 114. In the spaced bounded by the straight sides on the three prongs of the driver element 94, there is received a hexagonal driven head 34 which is mounted on a gear 106' meshing with the pinion 106. A plurality of rollers 94" are interposed between the prongs of the driver element 94, the surface of the recess 93, and the sides of the driven element 94".

As a preferred form of holding means or wrench to support a tool element by the arms 35, 36 there is shown in FIGS. 12 and 12a a U-shaped plate 115 having legs 116, 117 of substantially equal length, and supporting jaws formed by two pairs of pivotal latch fingers 118, one pair being arranged on each of the opposite faces of the plate. The opposite faces of the plate are machined to provide a U-shaped channel leaving thin flanges 119 adapted to fit in the grooves 67 defined on the opposite edges of the collar 60 of the adapter 53. The latch fingers which are L-shaped, are pivotally mounted in the channels and constructed to snap into latching relation with corners of the collar to hold the adaptor against accidental escape from the plate. Each latch finger 118 has a projection 121 at the tip which is adapted to fit over the corner of the adaptor collar to latch the adaptor. While other means of actuation may be employed for the fingers, in the present instance each pair of fingers are spring biased inwardly by an individual bow spring 122, to snap into latching relation with the adaptor collar. The inclined outer edges 121' of the tips of the fingers provide for camming them far enough apart to embrace the adaptor collar 60, upon adjustment of the arm and the holding means outwardly from an inward position adjacent the track 33 to seize the adaptor. To release the latch fingers an assembly is provided including a crosspin 123 utilized to engage both bowsprings of the composite latch finger assemblies on the arm 35 at about the middle of the springs. The pin 123 is moved in a direction to bend the center of the bowsprings toward the latch fingers tending to pivot the latter outwardly and away from the collar of an adaptor seated between the legs of the wrench. To move the pin 123 a rod 124 is mounted in a passage in the plate 115, and connected at the opposite end to a pair of toggle links 125 joined by a roller 126. To flatten the toggle linkage and thereby move the rod 124 in a direction to open the latch jaws 118, a bar 127 is connected to the rod 95 and mounted for relative longitudinal movement on the plate 115 into engagement with the roller 126. A spring 128 acting against the plate 115 and the bar 127 urges them apart but permits relative movement to an extent that affords actuation of the jaws to release a tool element. In the operation of the unit with the holding means supporting a tool element in a socket, when the gearing of the head 30, 31 is operated to draw the holding means inwardly, the plate 115 is held momentarily against movement while the bar 127 is actuated against the spring 128 to engage the roller 126 of the toggle links 125, flattening the toggle and thereby operating to open the latch fingers and releasing the tool element from the holding means.

Since a tool element T in the machine tool spindle socket 65 after the spindle 14 has stopped rotating may be left cocked slightly with respect to the vertical, the pickup of the tool element T may be facilitated by including means for squaring the position of the tool element adaptor prior to its being engaged by the holding means. This could be accomplished by turning the spindle so that the adaptor is properly positioned. However, reference is made to FIGURES 15 and 16 for the purpose of describing an alternative form of the holding means which includes an arrangement for orienting the tool element adaptor itself prior to pick-up. According to this aspect of the invention a pair of orienting members may be substituted for the U-shaped plate 115 shown in FIG. 12 as providing one means of support for the tool element.

The orienting members comprise an L-shaped member 130 having a finger 131 engageable with the tool element adaptor (FIG. 15), and a U-shaped member 132 having a pair of parallel, spaced legs 133, 134 of substantially different length. These members are separated by a spring 135, which permits relative movement of the members by compressing the spring, and are movable together, in the leading, lagging relation shown in FIG. 15 into engagement with the collar of a tool element adapter. The orienting members 130, 132 are arranged to turn the collar of the tool element adaptor 53, and thus the tool element, when it is initially cocked as shown in FIG. 15, either clockwise or counterclockwise depending on the particular angle at which the tool element happens to be cocked. With the collar of the adaptor turned from about 45 or less counterclockwise from its square position, the tip 131 of the member upon contacting the collar as shown in FIG. 15, tends to rotate the tool element clockwise until it squares up, whereupon the legs 133, 134 of the U-shaped member 132 slip into the slots 67 in the opposite sides of the collar and cause it to be positioned exactly. In the final stages of the movement of the members, the L-shaped member 130 is in abutment with the edge of the collar, while the U-shaped member 132 completes its movement relatively to both the adaptor collar and the companion orienting member then stationary, this resulting in the spring 135 being compressed between the members.

When, on the other hand, the adaptor is located counterclockwise by an angle substantially greater than 45, the longer left leg 133 of the U-shaped orienting member 132 upon engagement within the slot 67 in the collar, tends to turn the latter counterclockwise to its final square position with the opposite leg 134 being sufficiently shorter to allow the adaptor collar to turn to its proper position without interference. The finger 131 upon engagement with the collar is inefiective to turn the latter, and, therefore, initially the L-shaped orienting member 130 is stopped in its forward movement, while the companion U-shaped member 132 advances compressing the spring and engaging the collar.

Pairs of latch jaws 136 similar to the latch jaws 118 of FIG. 12 and operable in a similar fashion may be included with the present orienting members as part of the holding means, serving to latch the adaptor against accidental release. The latch jaws may be mounted in any convenient manner, for example, on the body of the member 132.

In the operation of the tool carrier of FIG. 12, to move a tool element in the requisite manner between the drum 20 and the spindle 14, the adaptor is first gripped by the wrench or holding means. The tool element is then ejected from one socket, and carried by the respective tool carrier head through successive longitudinal and lateral paths to the other socket. For example, the lower head 31 is shown in FIGS. 3 and 12 with the arm 35 holding the tool element T in the machine tool spindle 14. The power drawn bolt 70 by reverse rotation is used to forcibly eject the adaptor, and the tool element T, therefrom. The head 31 is moved longitudinally of the spindle to clear the adaptor from interference. For this purpose an advancing screw 137 power driven from the transmission of the machine tool head, is provided adjacent the spindle. By means of the screw 137, connected to move the head 31 by a hollow threaded shaft 138, the head 31 may be moved to extract a tool element from the spindle, or by operation in the reverse direction, to insert therein a tool element held in alinement with the spindle socket.

At the end of the track 33 adjacent the drum 20, the screw 139, power driven from the spindle drive, provides means for shifting the head 30 axially of the drum during the operation of extracting or inserting a tool element 21 therein. Referring to FIG. 3, the sildable head 30 on the upper edge of the H-shaped track 33 is movable longitudinally thereof by a nut 146 connected to the head, and, by means of the screw 139, may be located at the right end of the track 33 so as to be positioned adjacent the drum 20 at the rear of the machine tool column 12 as shown in dash-dot outline. With the storage drum 20 stopped so that a selected tool element 21 is positioned at the receiving station where it may be reached by the holding means supported on the extensible arm 36, the latter is moved to pick up the tool element so that it may be transferred to the machine tool spindle. The head 31 is traversed to a position spaced from the drum 20 sufficiently far so as to avoid interference between the shank of the adaptor and the sleeve socket. In order to insert a tool element, held by means of its adaptor, within an empty socket in the drum, as previously set forth the power driven screw 110 is rotated to operate the extensible arm 36 through the rack and pinion drive 101 so that the arm 36 is moved radially outward to a position where the tool element is alined with the empty socket. The head is then traversed, again by means of the screw 139, to insert the shank of the adaptor into the empty socket in the drum sleeve, and the draw bolt 75 operated to lock the tool element therein.

The operation is reversed to extract a tool element from the drum. Accordingly, after having been located adjacent the drum by the screw 139, the mechanism on the head 30, 31 is operated to move the holding means carried by the arm 36 into engagement with the selected tool element in the drum sleeve 41 and the tool element is secured against release. The draw bolt 75 in the socket of the drum sleeve 41 may be employed to eject the tool element from the socket by reverse driving the draw bolt through the belt drive 82, and the head 31 operated through straight line movement to transfer the tool element out of the matrix socket and by continuing straight line movement to transfer said tool element to the spindle end of the track 33 into a position laterally adjacent the forward end of the spindle.

To reverse the positions of the heads 30, 31 above and below the track 33 and thereby move said tool element laterally from said position into alignment with the spindle socket, the end section 33" of the track is indexed by power means connected to the spindle drive. In this manner the head 31 bearing the tool element T removed from the spindle 14 is positioned above the track 33 while simultaneously the head 30 carrying the tool element 21 extracted from the drum 20, is swung below the track so as to be movable into position to insert the tool element in the spindle socket. After the tool elements have been inserted within the sockets in the spindle and drum respectively, and the holding means released by opening the latch jaw 118, the heads 30, 31 and arms 35, 36 carried thereby may be moved to an at rest position, for example drawn in against the track 33, and out of the way during the machining operation.

To summarize the operation of the tool carrier, the tool carrier drive is shown schematically in FIG. 3, with the track 33 including its sections 33', 33" extending between the spindle 14 and drum 20. The dual heads 30, 31 are shown having holding means carrying tool elements T, 21 in the process of being exchanged between the drum and spindle.

For operating the heads to move lengthwise of the track 33, power driven screws 137, 139 are provided. The longer of these screws 139 extends parallel to the track 33 for substantially its full length. An internally threaded nut 140 is movable lengthwise of the track by rotation of the screw 139 and is connected by a tongue and groove to move the head (30 or 31) longitudinally of the track from a point adjacent the drum 20 to a point adjacent the spindle 14. The shorter of these screws 137 is located adjacent the spindle and such as to operate by means of a longitudinally movable, hollow, threaded shaft 138 the head 30 or 31 slidable along the under edge of the track section 33" during the process of inserting or removing a tool element from the spindle 14.

As indicated in FIGS. 3 and 12, each head 30, 31 includes a rack and pinion drive 101 for moving the extensible arm 35, 36 and holding means radially relative to the track 33. Power is supplied to the heads for this purpose by, alternately, a power screw 107 located adjacent the spindle, or a power screw 110 located adjacent the drum. The screw 107 located adjacent the track at the end near the machine tool spindle is received within a hollow shaft 111 which is connected to the rack and pinion drive 101 by a tongue 111 received in the groove formed in the shaft 113 carried by the head and forming part of the rack and pinion drive. Thus, one of the arms 35, 36 may be operated by the latter screw 107 to pick up from or insert a tool element in the socket of the spindle 14. Upon revolving of the section 33" of the track, at the spindle end, the heads 30, 31 are swung between above and below, and are, as an incident to this movement, separated from operative engagement with the drive screws on one side of the track and brought into operative engagement with the screws on the other side. The tongue and groove method of connection between the heads and power screws permits the operation in this manner.

In addition to the power means described, there is at the end 33 of the track 33 adjacent the drum 20, the power driven screw 110 and nut 112 operated thereby which is adapted to be connected to the shaft 113 of the rack and pinion drive 101 for the heads 30, or 31, whichever happens to be positioned at that end of the track 33. In the arrangement shown, the nut 112 may be engaged in and disengaged from the collar 113' carried by the shaft 113, by turning the nut 112 to free the projection 112' carried thereby, from the collar 113', and means (not shown) are provided for this purpose. Thus the arm 35, 36 may be moved to shift the holding means between a sleeve in the drum and a position adjacent the track 33, in the operation of transferring the tool element T from the spindle to the drum, or a selected tool element 21 from the latter to the spindle.

The location of limit switches LS 1-5 is also shown in FIG. 3, which switches form part of a control circuit for operating the tool carrier. Operation of the tool carrier begins with the heads 30, 31 of the latter drawn in against the track 33 in the at rest position, with the end of shaft 111 to the right from the position shown in FIG. 3, ins contact with LS 1, and shaft 137 in contact with At the start of the cycle, the holding means carried by the arm 35, which is positioned adjacent the track 33, is advanced in a radial direction toward the tool element by the power driven screw 107 which is operated to move the shaft 111, and via the rack and pinion drive 101, to extend the arm 35 so as to move the holding means into engagement with the tool element T within the spindle socket. Limit switch LS 2 is located to be tripped by the end of the shaft 111 when the holding means is positioned to grip the tool element. The operation of limit switch LS 2 in turn causes shaft 138 to be advanced by the operation of the screw 137 which actuates this shaft, far enough to free the shank of the adaptor on the tool element from interference with the spindle. In order that the radial position of the holding means remains the same during this latter movement longitudinally of the spindle, the shaft 111 continues to be operated by the screw 107 in synehronism with the shaft 138, and the movement of the head. The limit switches LS 3 and LS 5 are positioned to be contacted by shafts 111 and 138, as shown in solid lines in FIG. 3, at the completion of their stroke, when the head 30 is prepared to be revolved or indexed During the previously described operation of the tool handling mechanism associated with the head 30, the head 31 on the upper edge of the track is moved to position a tool element opposite the spindle and ready for tool changing.

The indexable section 33" of the track 33 carrying the tool carrier heads 30, 31, is then rotated by a gear drive including the gears 34, 34, and the head below the track subsequently, operated to insert the selected tool element in the spindle and then separated therefrom while the head on the upper side of the track speedily transfers the other tool element into the drum.

There are in addition to the limit switches LS 1-5 an associated set of limit switches (not shown) for operating during return movement of the power screws and shafts to their initial position. For reversing the drive any convenient arrangement may be employed, such as reversing clutches B, C, adapted to reverse the direction of operation of the power screws as required.

System of tool identification In order to provide a fully automatic tool changing system, in carrying out one of the important objects of the invention, each tool element of a set of tool elements which is adapted to be employed in the machine tool shown in the drawings, is provided with means of identication which serves to distinguish it from the others of the set. Furthermore the tool element is selected for the tool changing operation directly by its identification. Referring to FIG. 5, as previously noted, each tool element 21 which may be drill, tap, milling cutter, or the like, is received, in a standard type adaptor 53. The adaptor provides a tapered shank 52 which is formed so that the tool element may be received in the socket 65 of the machine tool spindle, or, alternatively, in the sockets '51 of the storage drum or matrix 20. For the purpose of identifying the tool element 21 mounted in each adaptor, a portion of the tapered shank of the adaptor is marked in a manner which may be read by means provided in the apparatus. For exemplary purposes, a preferred arrangement is shown in FIG. 10 as comprising a systematic arrangement of parallel, peripheral grooves 140 although the markings may be varied as desired.

Referring to FIGS. 5, l and 11, it will be seen that a coded binary system of identification for a set of tool elements 21 up to 9,999 in total number may be provided utilizing 16 zones or positions for grooves 140 on the shank 52. It is general practice to neck down the shank 52 slightly, intermediate the tapered portion, or to relieve the socket at its midpoint, to provide clearance between the wall of the socket and the surface of the shank at the midpoint of the taper. This portion of the surface of the adaptor shank, therefore, may be used for identification purposes without impairing the normal function of the adaptor to provide for carrying the tool element without play in the socket of the machine tool spindle.

As shown in FIG. 5, for exemplary purposes the shank of the adaptor is provided with a predetermined order of parallel grooves. The system illustrated with the aid of the chart in FIG. 11 contemplates the said 16 zones or positions, which may be grooves or not grooves on the shank, with the presence of a groove at a zone indicated by the numeral 1 in the chart, while the unmachined surface or no groove is designated by a zero.

The zones according to this system comprises 4 groups of 4 places each, the groups corresponding to the units order, tens order, hundreds order, and thousands order. Each place of a group is assigned an arbitrary value, indicated just below the order designation in FIG. 11, of 8, 4, 2 and 1, which values allow by appropriate combination, an indication of any number 09. For example, the decimal number 871, in the left column, may be indicated by grooves in the hundreds, tens, and units order. In the hundreds order grooves are indicated at the first place (reading from the left) with a "no groove, at the other places, the arbitrary value assigned to the first place eing equal to 8. Similarly in the tens order, the sum of the values for grooves at the second, third and fourth places (4+2+1=7) is equal to 7; and the single groove in the fourth place (1) in the units order indicates the number 1. Therefore, grooves provided at the zones on the shank in accordance with the chart of FIG. 11, provide a means of identification for individually distinct tool elements received in the adaptor so identified.

In keeping with the present invention, means is provided for automatically selecting a particular tool element, and transferring the latter to the machine tool spindle responsive to the identification on the shank of the adaptors provided by the coded system of grooves, while the adaptors and tool elements are carried in the storage drum or matrix. For this purpose, each sleeve 41 in the storage drum is provided with a set of reading pins which contact the shank of the adaptor positioned in the socket. Springs 146 are used to bias the pins 145 inward of the sleeve 41. The reading pins 145 are used to actuate a reading device 147 which is connected in the control circuit, as shown schematically in FIG. 10. As shown in FIGS. 8 and 9, the reading device 147 is fixedly mounted adjacent the drum and arranged to be contacted by the reading pins of each sleeve in the drum. Accordingly, as shown in FIG. 10 the reading device includes a total number of 16 plunger actuated on-otf switches 150 A-P, one corresponding to each of the zones and connected in parallel in the control circuit shown in FIG. 10. As shown in FIGS. 8 and 9 the switches 150 A-P are located in a row under one end of a set of actuating mechanisms 151. Each mechanism includes a fixed base plate 152 carrying a vertically movable acutator bar 153 provided with a curved upper edge 154 which is contacted by the corresponding pin 145 as the socket in the drum swings past. The actuator bar 153 is lifted from the base plate 152 by the lug 154 of the switch, which is spring biased to a raised position. To insure uniform movement of the actuator bar 153 it is connected to the base plate by spaced levers 156 pivotally mounted on the base plate and providing a parallelogram linkage with the latter and the actuator bar.

In the operation of the tool changing system, a particular tool element is located in a record controlled seek or hunt cycle during which the drum or matrix is rotated, successively bringing the set of reading pins 145 associated with each sleeve 41 to a location where they may be read by means of the fixed reading device 147.

Referring to FIG. 10, a control is shown for the operation of the storage drum 20, which in the present case iS driven via a clutch and gear transmission 26 as shown in FIG. 2, from the drive motor 17 for the machine tool spindle. The clutch controlling the operation of the storage drum 20 may be controlled electrically by means of a clutch coil 166 (FIG. 10) which is energized at the the start of the seek cycle to engage and cause the drive motor to drive the storage drum or matrix 20.

An exemplary control circuit for the operation of the clutch coil 166, shown in FIG. 10, includes a set of record controlled microswitches 170 AP arranged in parallel with each other and in series with the individual switches 150 A-P of the reading device 147 associated with the storage drum. By setting the microswitches 170 AP in the pattern identifying a particular tool element, the relay coil R-172 which is energized by the circuit when the switch 177 is closed remains energized until the reading device 147, brought into association with the sleeve containing the so-identified tool element, opens the circuit through each of the total number of branches, thus deenergizing the relay coil R472. The relay 172 drops out opening the circuit including the clutch coil 166. It is, moreover, contemplated that an associated brake 175, which may be spring actuated, for example, or electrically actuated is so desired, responsive to the deenergization of the clutch coil 166, shall be employed to stop the rotation of the drum at a precise point so that the sleeve containing the selected tool element is positioned at the receiving station accessible to the tool carrier.

The individual microswitches of the set 170 A-P in the control circuit shown in FIG. 9, may be controlled in a number of different ways depending on the type of automatic control desired. As a preferred embodiment, it

13 is contemplated that these on-off microswitches 170 A-P may be record controlled as by magnetic tape or paper tape or through a punch card or similar record and set in accordance with the code identification for a particular tool element to be used in the machine tool, prior to the seek cycle.

A seek relay R-177 under the same record control is caused to close and begin the seek cycle. Thus, the control circuit shown in FIG. is energized and the storage drum 20 is caused to rotate at high speed moving the sets of pins in each sleeve into contact with the fixed reading device.

The tool changing system illustrated herein is applicable to large, massive machine tools, of a size for mounting tool elements adapted to take a cut up to 6" in diameter and movable through a cutting stroke of about 18". Such tool elements are of substantial size and weight. The storage matrix shown has a capacity of more than 30 of such tool elements, and has a weight of several tons with the tool elements received therein. It is contemplated that during the hunt period the matrix is to be rotated to provide about 200' per minute linear speed at the sockets, in order to reduce to a minimum the time required to locate a desired tool element.

Moreover, the tool carrier and matrix may be operated at high speeds to reduce to a minimum the time required to transfer a tool element between the spindle and the matrix. And since the tool element T extracted from the spindle is, with the random access tool changing system illustrated herein, returned directly to the empty matrix socket, no time factor is involved for seeking a particular place for storage of the tool element, as in other types of systems.

Therefore, it is an important advantage of the random access tool changing system that the tool changing operations may, in the interest of maintaining high machining accuracies, be operated solely during dead eriods in the machining process. Dead periods in which the tool element mounted in the machine tool does no cutting are a part of any machining process, for example, during the retraction of a drill. However, such periods are normally of very short duration. Because of the tool changing speed possible with the present system, such periods, although of short duration, can be employed for the tool changing operations.

Therefore, the system and apparatus of the invention disclosed herein is completely flexible and permits programming of complicated machining operations, with diverse tools, yet achieving high machining accuracies with the machine tool incorporating the invention.

I claim as my invention:

1. In combination, a machine tool having a power driven spindle including means for receiving a tool ele ment, means carried longitudinally spaced from the forward end of said spindle defining a movable matrix of compartments for storing a set of tool elements each adapted to be mounted in said spindle, means for moving said matrix to locate a selected tool element of said set in a loading position for transfer to said spindle, a pair of independently movable tool carrier means for exchanging tool elements from both the spindle and the matrix including a tool carrier for extracting said selected tool element and transferring it from the matrix to the spindle, means including an elongate track extending between said matrix and a position adjacent said spindle for mounting said tool carrier for straight line movement to transfer said selected tool out of the matrix and by continuing said straight line movement to transfer said selected tool to an intermediate position laterally adjacent said spindle, power means for moving said tool carrier along said track, means including a gripping member carried by said tool carrier for movement into engagement with a selected tool element at said loading position and operative upon such engagement to seize the latter for transfer to said intermediate position, and means for transferring said selected tool from said intermediate position to said spindle.

2. In a machine tool having an elongate power driven spindle including means in its forward end for receiving a tool element, the combination comprising, means defining a movable matrix of compartments for storing a set of tool elements each adapted to be mounted in said spindle, means for moving said matrix to locate a tool element of said set in a loading position spaced both longitudinally and laterally from the forward end of said spindle, means including independently movable tool carriers for exchanging a selected tool element in said loading position in the matrix with an old tool element in the spindle, means supported between said spindle and said matrix for mounting one of said tool carriers for longitudinal movement independently of the other of said tool carriers for movement of a selected tool element to an intermediate position laterally adjacent the forward end of said spindle from said loading position in the matrix, and means on said machine tool for supporting said other tool carrier for lateral movement of an old tool element removed from said spindle to said intermediate position while said selected tool element is simultaneously transferred laterally from said intermediate position to a position forward of said spindle.

3. In a machine tool having a power driven spindle including means for receiving a tool element, the combination comprising, means including a rotary drum defining a ring of sockets for storing a set of tool elements each adapted to be mounted in said spindle, means for mounting said drum rearwardly of and for rotation about an axis parallel to the spindle, means for rotating said drum to position a tool element of said set in a loading position for transfer to said spindle, said loading position being rearwardly and laterally located relative to said spindle, a pair of independently movable tool carriers providing means for simultaneously gripping tool elements from both said spindle and said drum for transferring said tool elements therebetween, means for mounting one of said tool carriers on said machine tool for movement longitudinally of said spindle between a position laterally adjacent the forward end of said spindle and a position adjacent said drum, and gripping means included on said tool carriers operative to seize a tool element in said loading position and in said spindle for transfer between said drum and said spindle.

4. In a machine tool having a power driven spindle including means in its forward end for receiving a tool element, the combination comprising, means including a rotary drum defining a ring of sockets for storing a set of tool elements each adapted to be mounted in said spindle, means for mounting said drum rearwardly of said forward end of and for rotation about an axis parallel to the spindle and spaced from said spindle a distance substantially less than the radius of the ring of sockets, a pair of independently movable tool carriers providing means for simultaneously gripping tool elements from both said spindle and said drum for transferring said tool elements therebetween, means for mounting one of said tool carriers on the machine tool including a track supported parallel to said spindle extending from a position laterally adjacent the forward end of said spindle to a position adjacent said drum radially inward of said ring of sockets, power means for rotating said drum to position a tool element of said set in a loading position adjacent said track, and gripping means mounted on said tool carriers including a member selectively operable to seize said tool element while in the loading position in the drum and to release the tool element.

5. In a machine tool having a support means, and a power driven spindle carried by said support means and including a socket for receiving a tool element, the combination comprising, a rotatable drum carried by said support means including a ring of sockets defining a matrix for storing a set of tool elements each adapted to be mounted in the socket of said spindle, a pair of independently movable tool carrier means for simultaneously gripping tool elements from both said spindle and said matrix and for extracting a tool element from one socket and transferring it between the matrix and spindle to another socket including a track carried by said machine tool extending between a position laterally adjacent said Spindle and a position adjacent said drum, means for rotating said drum to locate a tool element of said set in a loading position adjacent the track, one of said carrier means including a tool carrier movably mounted on said track for movement between said positions, said carrier comprising a head movable along said track, a member carried by said head including gripping means operative to seize a tool element for transfer to said spindle, and power means operative to move said tool carrier along said track to said matrix to pick up the tool element for transfer to the spindle.

6. In a machine tool having a power driven spindle including means for receiving a tool element, the combination comprising, means including a rotary drum defining a ring of sockets for storing a set of tool elements each adapted to be mounted in said spindle, means for mounting said drum rearwardly of said spindle for rotation about an axis parallel with said spindle, power means for rotating said drum to locate a tool element for transfer to said spindle at a loading station in vertical alinement with the spindle, means including a tool carrier for transferring a tool element between the drum and spindle, means for mounting said tool carrier on said machine tool including a track supported parallel to said spindle at an intermediate level between the latter and the loading station and extending from a position adjacent said drum and a position adjacent said spindle, means including an indexable section of said track adjacent said spindle for swinging said tool carrier with a tool element held thereby between the side of the track facing the loading station and the opposite side of the track facing the spindle, and gripping means included on said tool carrier operative to seize a tool element, and after transfer to the spindle, to release said tool element.

7. In a machine tool having a horizontal power driven spindle including a socket for receiving a tool element, the combination comprising, means including a rotary drum mounted on said machine tool defining a ring of sockets for storing a set of tool elements each adapted to be mounted in said spindle, means for mounting said rotary drum on said machine tool rearwardly of said spindle and for rotation about a horizontal axis, power means for rotating said drum to position the socket containing a tool element for transfer to said spindle at a loading station in vertical alinement with said spindle, means including a tool carrier for transferring a tool element between the drum and spindle, means for mounting said tool carrier including a horizontal track supported on said machine tool above said spindle substantially midway between the spindle and the loading station and extending from adjacent said spindle to adjacent the drum, so that the radial distance between said track and a drum socket located at said loading station is about the same as the radial distance between said track and said spindle socket, gripping means included on said tool carrier operative to seize a tool element from the drum socket located at the loading station for transfer to the spindle, and means including an indexable track section atthe end of said track adjacent the spindle for swinging said tool carrier be tween the upper side of the track facing the drum and the under Side of the track facing the spindle.

8. In a machine tool having a power driven spindle including means for mounting a tool element, the combination comprising, means defining a matrix of compartments for storing a set of tool elements each adapted to be mounted in said spindle, means including a tool carrier for exchanging a tool element mounted in said spindle for a selected tool element in one of said compartments in said matrix, a track for said tool carrier extending between a point adjacent said spindle and a point adjacent said matrix compartment, said track having an indexable section at the spindle end, means on opposite sides of said indexable track section defining ways, drive means for indexing said indexable track section, said track having a fixed section extending to the matrix presenting a way on the side of said track adjacent said matrix compartment, a pair of heads carried by said track for movement along said ways, each of said heads including a member supported for movement away from said track toward a tool element in said spindle or toward said selected tool element in said matrix compartment, holding means carried by said members operative to seize said selected tool element in said matrix compartment for one of said heads and a tool element in said spindle for the other head upon movement of said holding means into engagement with the respective tool elements, and means operative to cause movement of both said heads to an adjacent position on said indexable track section, the latter being indexable to exchange the positions of said heads for transfer of the selected tool element to the spindle and the other tool element to said matrix compartment.

9. In a machine tool having a power driven spindle including a socket for receiving a tool element, the combination comprising, means defining a matrix of sockets for storing a set of tool elements each adapted to be mounted in the socket of said spindle, means for extracting a tool element from a socket in the matrix for transfer to the spindle socket and for extracting a tool element from the spindle socket for return to the matrix including a fixed longitudinal support carried by said machine tool extending between said spindle and said matrix, means for moving said matrix and support relative to each other to position the socket containing a tool element adjacent the matrix end of said support, tool carrier means including a pair of heads slidable on said support between said spindle and matrix, and means including a gripping member carried by each of said tool carrier heads for movement respectively into engagement with the selected tool element in the matrix and a tool element in the spindle and operative upon such engagement to seize said tool elements for transfer.

10. In a machine tool having means for mounting a tool element including an elongate socket, an adaptor having an elongate shank adapted to be received in said socket with one end extending therefrom, a collar mounted on the projecting end of said shank, and means including a tool carrier mounted for movement axially of said socket for extracting a tool element supported in said socket by said adaptor, the improvement comprising, holding means including a member supported by said tool carrier for movement in a lateral direction relative to the axis of said socket and having a grip operative to seize said adaptor collar, and drive means for moving said tool carrier axially relative to said socket to separate the adaptor therefrom.

11. In a machine tool according to claim 10, wherein said grip comprises spaced legs operative to seize the adaptor collar, and latch means mounted on said member and cooperating with said spaced legs and said adaptor collar to positively secure the tool element against movement in said holding means.

12. In a machine tool according to claim 10, wherein said tool element includes a polygonal collar on the tool shank, said grip includes spaced legs operative to seize the opposite, parallel sides of said collar, and said latch means is engageable with the corners of said collar to positively secure the tool element against movement in said holding means.

13. In a machine tool having a power rotatable tool support including an elongate socket, the combination comprising: an adaptor for supporting a tool element in said socket, said adaptor including a shank receivable in 17 said socket and a collar having opposite parallel sides mounted on one end of said shank; means including a tool carrier movably mounted adjacent said tool support for extracting and inserting an adoptor and a tool element supported thereby in said socket, fixed means supporting said tool carrier for movement longitudinally of said tool support socket, gripping means carried by said tool carrier for movement in a lateral direction relative to said longitudinal movement of said tool carrier and operative to seize the opposite parallel sides of the collar of an adaptor, drive means for moving said gripping means to position an adaptor in said lateral direction, and drive means for moving said tool carrier and said tool socket relatively longitudinally to extract an adaptor therefrom and to insert an adaptor therein.

14. In a machine tool, the combination comprising, a rotatable spindle having a socket, means for mounting a tool element in said socket including an adaptor having a shank received in said socket with one end extending thererfom, a polygonal collar mounted on the projecting end of said shank, means including a tool carrier mounted adjacent said socket for extracting a tool element supported in said socket by said adaptor, holding means including a member supported by said tool carrier for movement in a direction toward the adaptor having parallel legs of substantially different length extending toward the adaptor and spaced to seize opposite parallel sides of said adaptor, the longer of said legs being engageable with the adaptor collar prior to the other leg to rotate the spindle so as to aline said collar with said legs, means mounted on said member to engage corners of said adaptor collar to secure the latter against release, and drive means for moving said tool carrier relative to said spindle to eparate the adaptor therefrom.

15. In a machine tool, the combination comprising, a rotatable spindle having a socket, an adaptor supporting a tool element and having a shank received in said socket With one end extending therefrom, a polygonal collar mounted on the projecting end of said shank, means including a tool carrier mounted adjacent said spindle for extracting a tool element supported in the socket thereof by said adaptor, holding means including a plate member supported by said tool carrier for movement toward the adaptor, means on said plate member including spaced parallel legs of substantially different length extending toward said spindle and operative to seize opposite parallel sides of said adaptor collar, means including an orienting device mounted on said plate member for alining said collar with said legs, said orienting device comprising an offset finger mounted adjacent the shorter leg of said plate member and resiliently positioned in advance of said member to engage the adaptor collar prior to said plate member so as to rotate the spindle in the direction of movement of the offset finger when the adaptor collar is cocked about 45 or less in that direction from an alined position, the longer leg of said plate member being arranged to engage the adaptor collar upon retraction of the offset finger when the adaptor collar is cocked more than 45 in said direction, to rotate the spindle in the opposite direction to an alined position, and drive means for moving said tool carrier relative to said spindle to separate the tool element therefrom.

16. In a machine tool the combination comprising, a rotatable spindle having a socket, a tool element supported in said socket having a collar mounted adjacent the front of the spindle, gripping elements on opposite sides of said collar, means for extracting said tool element from the spindle including a holder comprising a member supported for movement toward the tool element, gripping means on said member arranged to cooperate with said gripping elements for seizing said collar, means including an orienting device mounted on said member and movable into engagement with the collar of the tool element to rotate the spindle to a position in which said gripping elements are alined to receive said gripping means, said 18 orienting device comprising an offset finger mounted on said member and resiliently positioned in advance thereof to engage said collar prior to said member so as to rotate the spindle in the direction of movement of the offset finger to said alined position.

17. In combination with a machine tool having a power driven spindle, a set of tool elements each having a shank formed to be received in said spindle, systematic identification means on each shank for distinguishing the respective tool element from the others of said set, means defining a complex of matrix compartments for storing said set of tool elements, each of said matrix compartments being formed to receive said shank of a tool element, and a reading device in each compartment of said matrix actuated upon insertion of a tool element shank therein by said identification means thereon.

18. In a machine tool having a power driven spindle, the combination comprising, means defining a row of matrix compartments for storing a set of tool elements, an adaptor for supporting a tool element of said set in said spindle, said adaptor comprising a shank formed to be received in said spindle, each of said matrix compartrnents being formed to receive said shank, a systematic arrangement of identification grooves in the surface of said shank for distinguishing a tool element carried thereby from others of said set, a set of reading pins in each compartment of said matrix actuated by said identification groove upon insertion of an adaptor carrying a tool element therein, and means mounted adjacent said row of matrix compartments for reading said reading devices.

19. In combination, a machine tool having a workpiece support, an upright member adjacent said support, a horizontal power driven spindle carried by said upright member, a tool element storage drum carried rearwardly of the forward end of said spindle and mounted for rotation about a horizontal axis parallel with said spindle, means included in said drum defining an annular row of sockets coaxial with said horizontal drum axis and horizontally spaced from said spindle for storage of a set of tool elements, the axis of said spindle extending through said drum inwardly of said row of sockets, and tool changing means for transferring a tool element between said storage drum and said spindle, said tool changing means comprising a tool carrier movably mounted for horizontal movement between said drum and spindle from a loading station adjacent said storage drum to a tool exchange station adjacent said spindle, a horizontal track extending rom said loading station adjacent said drum to said tool exchange station adjacent said spindle for supporting said tool carrier for movement between said stations, said storage drum being rotatable to bring a tool element stored in one of said sockets to a loading position adjacent the track, means including a selectively operable gripping device carried by said tool carrier and operative to seize a tool element in a storage drum socket located at said loading position, power means for moving said tool carrier while gripping a tool element along said track from said loading station to said tool exchange station, and means for exchanging a tool element in said spindle with a tool element at said tool exchange station.

20. In combination, a machine tool having a horizontal power driven spindle, a tool element storage drum carried rearwardly of said spindle and mounted for rotation about a horizontal axis parallel with said spindle, means included in said drum defining an annular row of sockets coaxial with said horizontal drum axis and longitudinally spaced from the forward end of said spindle for storage of a set of tool elements, and a pair of independently movable tool carrier means for simultaneously gripping tool elements from both said spindle and said drum for transferring said tool elements therebetween, said tool carrier means comprising a tool carrier movably mounted for horizontal movement between said drum and spindle from a loading station adjacent said storage drum to a tool exchange station adjacent said spindle, said storage drum being rotatable to bring a tool element stored in one of said sockets to a loading position adjacent said loading station, means including a selectively operable gripping device carried by said tool carrier and operative to seize a tool element in a storage drum socket and located at said loading position, power means for moving said tool carrier horizontally from said loading station while gripping a tool element to extract the latter from said storage drum socket and to move said tool element to said tool exchange station, and means for exchanging a tool element in said spindle with said tool element at said tool exchange. station.

21. In combination, a machine tool having a horizontal power driven spindle, a tool element storage drum carried rearwardly of said spindle and mounted for rotation about a horizontal axis parallel to said spindle, means included in said drum defining an annular row of sockets coaxial with said horizontal drum axis and longitudinally spaced from said spindle for storage of a set of tool elements, and tool changing means for transferring a tool element between said storage drum and said spindle, said tool changing means comprising means for extracting a tool element from a socket in said drum and moving said tool element along a straight line path parallel to said spindle to a tool exchange station in substantial vertical alignment with and above said spindle, tool exchange means mounted on a support substantially intermediate said tool exchange station and said spindle, said tool exchange means having oppositely arranged radially extending arms, a selectively operable tool element holding device carried by each of said arms for engagement with a tool element in said spindle or a tool element at said tool exchange station, and power means for revolving said tool exchange means about the axis of said support to exchange positions of tool elements held by both of said arms.

22. In combination, a machine tool having a horizontal power driven spindle, a tool element storage drum carried rearwardly of said spindle and mounted for rotation about a horizontal axis parallel to said spindle, means included in said drum defining an annular row of sockets coaxial with said horizontal drum axis and longitudinally spaced from said spindle for storage of a set of tool elements, and tool changing means for transferring tool elements between said storage drum and said spindle via a straight line path parallel to said spindle and extending between said drum and a tool exchange station in substantial vertical alignment with and above said spindle, said tool changing means including oppositely arranged radially extending tool exchange arms mounted on a support substantially intermediate said tool exchange station and said spindle, a selectively operable tool element holding device carried by each of said arms for gripping a tool element positioned in said spindle or a tool element positioned at said tool exchange station, and power means for revolving said tool exchange arms about the axis of said support to exchange positions of tool elements held by both of said arms.

23. In combination, a machine tool having a horizontal power driven spindle, a tool element storage drum carried rearwardly of said spindle and mounted for rotation about a horizontal axis parallel to said spindle, means included in said drum defining an annular row of sockets coaxial with said horizontal drum axis and longitudinally spaced from said spindle for storage of a set of tool elements, and tool changing means for transferring tool elements between said storage drum and said spindle via a path longitudinally adjacent said spindle and extending between said drum and a tool exchange station in substantial lateral alignment with said spindle, said tool changing means including oppositely arranged radially extending tool exchange arms mounted on a support substantially intermediate said tool exchange station and said spindle, a selectively operable tool element holding device carried by each of said arms for gripping a tool element positioned in said spindle or a tool element positioned at said tool exchange station, and power means for revolving said tool exchange arms about the axis of said support to exchange positions of tool elements held by both of said arms.

24. In combination, a machine tool having a horizontal power driven spindle, a tool element storage drum carried rearwardly of said spindle and mounted for rotation about a horizontal axis parallel to said spindle, means included in said drum defining an annular row of sockets coaxial with said horizontal axis and longitudinally spaced from said spindle for storage of a set of tool elements, and tool changing means for transferring a tool element between said storage drum and said spindle via a straight line path parallel to said spindle to a tool exchange station in substantial vertical alignment with and above said spindle, a track parallel to said spindle and extending from said tool exchange station to said storage drum, said tool changing means including tool exchange means having oppositely arranged radially extending arms, a selectively operable tool element holding device carried by each of said arms for engagement with a tool element in said spindle or a tool element at said tool exchange station, and power means for revolving said tool exchange means to exchange positions of tool elements held by both said arms.

25. In a tool storage magazine adapted to releasably support a plurality of tools; a plurality of tool receiving storage sockets carried by said magazine; a power actuated clamp mechanism associated with each of said storage sockets; power driven means connected to move said tool storage magazine for moving a preselected tool into a tool change ready station; means for releasing said clamp mechanism associated with the tool storage socket carrying the preselected tool in said ready station; and a power driven tool change arm including securing means operative to engage the released tool in said ready station and withdraw it from the associated storage socket.

26. The tool storage magazine of claim 25 in combination with a machine tool spindle having a tool receiving socket, in which said clamp mechanism associated with each of said storage sockets in said magazine comprises a power operated drawbolt engageable in a recess in a tool, and in which said spindle socket includes a power operated drawbolt engageable in a recess in a tool, for securing tools in the respective sockets.

27. In a machine tool having a power driven spindle including a socket on the front of said spindle, the combination comprising, a plurality of tools each having an adaptor constructed to be received in said spindle socket, said adaptor including a collar having opposite parallel straight sides presenting spaced gripping surfaces, and means for transferring a selected tool to said spindle including a pair of tool change arms mounted for rotation and longitudinal movement about a common support adjacent said spindle, each of said arms having power actuated means for gripping a tool adaptor including a pair of spaced elements mounted on the respective arm for relative movement and actuable from an open position straddling said gripping surfaces of the collar of a tool adaptor to a gripping position with the collar latched between said elements, and power means for revolving said change arms about the axis of said support to exchange positions of tools held by both said arms and for moving said arms longitudinally of said spindle for inserting tools in and withdrawing tools from said spindle.

28. In a machine tool having a power driven spindle including a socket and drive keys on the end of said spindle, the combination comprising: a plurality of tools each having an adaptor constructed to be received in said spindle socket and including a collar having longitudinal slots spaced to receive said spindle drive keys, said adaptor collar including opposite straight sides presenting spaced gripping surfaces; and means for transferring a selected one of said plurality of tools to said spindle in- 

